53 Pa. Stat. § 15556
It shall be lawful for, and the right is hereby conferred upon, cities of the first class of this Commonwealth to purchase, acquire, enter upon, take, appropriate, occupy, and use such lands, rights, and interests therein, property and franchises, within their respective corporate limits, and within the corporate limits of adjacent cities, boroughs, and townships, as shall be necessary for the acquisition, location, construction, maintenance, use, and operation of transit facilities, or any one or more of them, under the rights conferred by this act, including such lands and rights, and interests therein, as shall be necessary for future additions to and enlargements of such transit facilities, or of any one or more of them; also such lands and rights and interests therein as shall be necessary for the relocation of any track or tracks of existing railroads or railways, or of any pipes, sewers, subways, underground conduits, or ways, necessary to be removed and relocated in order not to interfere with the location, construction, maintenance, use, or operation of such transit facilities, or any one or more of them; and including, also, such lands and rights, and interests therein, as shall be necessary for the purpose of disposing of earth, stone, and other material excavated in he construction of such transit facilities, or any one or more of them: Provided, however, That the right hereby conferred shall not be taken as authorizing the taking or appropriating of any railroad or railway in operation in said cities.
53 P.S. § 15556